Pediatric Intensive Care Unit, Wolfson Medical Center, Holon, Israel.
Nutrition. 2013 Sep;29(9):1094-9. doi: 10.1016/j.nut.2013.03.013.
The metabolic response of critically ill children is characterized by an increase in resting energy expenditure and metabolism, and energy needs of the critically ill child are dynamic, changing from a hypermetabolic to hypometabolic state through the continuum of the intensive care unit (ICU) stay. It therefore appears essential to have a precise evaluation of energy needs in these patients in order to avoid underfeeding and overfeeding, loss of critical lean body mass, and worsening of any existing nutrient deficiencies. However, there are no clear definitions regarding either the exact requirements or the ideal method for determining metabolic needs. In clinical practice, energy needs are determined either by using predictive equations or by actual measurement using indirect calorimetry. Although many equations exist for predicting resting energy expenditure, their accuracy is not clear. In addition, very few clinical trials have been performed so that no firm evidence-based recommendations are available regarding optimal nutritional management of critically ill children and infants. Most studies have come to the same conclusion (i.e., current predictive equations do not accurately predict required energy needs in the pediatric ICU population and predictive equations are unreliable compared with indirect calorimetry). The recent American Society for Parenteral and Enteral Nutrition clinical guidelines for nutrition support of the critically ill child suggest that indirect calorimetry measurements be obtained when possible in pediatric patients with suspected metabolic alterations or malnutrition, according to a list of criteria that may lead to metabolic instability, thus making standardized predictive equations even less reliable. Although the standard use of indirect calorimetry is limited due to equipment availability, staffing, and cost, the accuracy of the commercially available devices continues to improve and the measurements have become more reliable and easier to perform. In the absence of sufficient data, prospective controlled studies need to be conducted in order to evaluate the benefit of tight calorie control achieved by accurately measuring the energy needs of the critically ill child. Optimizing measuring techniques could make this more feasible and decrease the need to rely on inaccurate equations while providing appropriate energy requirements.
危重症患儿的代谢反应表现为静息能量消耗和代谢增加，且危重症患儿的能量需求是动态的，通过重症监护病房（ICU）的连续治疗过程，从高代谢状态转变为低代谢状态。因此，对这些患者进行精确的能量需求评估似乎至关重要，以避免喂养不足和过度喂养、关键瘦体组织丢失以及任何现有营养缺乏症的恶化。然而，对于确切的需求或确定代谢需求的理想方法，目前尚无明确的定义。在临床实践中，能量需求是通过使用预测方程或通过间接测热法进行实际测量来确定的。虽然有许多预测静息能量消耗的方程，但它们的准确性并不明确。此外，很少有临床试验进行，因此，关于危重症儿童和婴儿的最佳营养管理，尚无确凿的循证推荐。大多数研究得出了相同的结论（即目前的预测方程不能准确预测儿科 ICU 人群的所需能量需求，与间接测热法相比，预测方程不可靠）。最近，美国肠外与肠内营养学会为危重症儿童的营养支持提供了临床指南，建议在疑似代谢改变或营养不良的儿科患者中，如有可能，根据可能导致代谢不稳定的一系列标准，获取间接测热法测量值，从而使标准化预测方程更不可靠。尽管由于设备可用性、人员配备和成本限制，间接测热法的常规使用受到限制，但商业上可用设备的准确性仍在不断提高，测量结果变得更加可靠且易于实施。在缺乏充分数据的情况下，需要开展前瞻性对照研究，以评估通过准确测量危重症患儿的能量需求来实现严格热量控制的益处。优化测量技术可以使这一目标更具可行性，并减少对不准确方程的依赖，同时提供适当的能量需求。
